Two possible things:
1) You colour system isn't set correctly in the output. You need to set it
to PAL (Most of the world ), SECAM ( France and Middle East and possibly
USSR ) or NTSC ( North America, South Korea, Myanmar and Japan ). You can
adjust this from the TV out options in the driver control panels. Your TV
should be able to handle 60 Hz modes for PAL/SECAM, as you may get a black
white picture if the TV doesn't support the mode supposedly.
2) Your colour system is set correctly, but you're using an S-Video to SCART
convertor block of some sort. Many of these don't convert the S-Video output
to SCART composite correctly. You can get a suitable adapter from
http://www.s-video.com/svideoscart.html. I've not actually used one of
these, though I have bought a few S-Video to Composite convertors from them.
